Rotor market strong on technology

Some currently in-production civil helicopters derive from designs many years old, validating their excellence but seeking yet their improvement.

Others emerge as new designs that pursue greater levels of capability commensurate with evolved general and specific requirements.

Two prime areas are reduced environmental effects and increased range for offshore helicopters.

 

AgustaWestland

AgustaWestland developed the AW119 Ke (Koala enhanced) light single-engined helicopter through the A119 Koala from the well-established A109.

With a maximum gross weight (MGW) of 2880kg, it seats eight persons including one or two flight crew and uses a 750kW Pratt & Whitney Canada PT6B-37A turboshaft engine, high-strength cocoon-type airframe and dual independent Stability Augmentation System (SAS).

It could undertake utility, fire-fighting, law enforcement, emergency medical services (EMS) with two litters and two medical attendants, search and rescue (SAR) and executive and offshore transport roles.

In February 2010 AgustaWestland and India-based Tata Sons agreed to form a joint company to assemble AW119s, with first delivery planned for 2011.

Another, this time twin-engined, development of the A109, the Grand New, which emerged through the Grand, with a maximum take-off weight (MTOW) of 3180kg, could carry one or two crew and seven or six passengers.

It uses 550kW full-authority digital engine control-equipped (FADEC) Pratt & Whitney Canada PW207C engines, a cocoon-type airframe and an array of advanced avionic systems including a Synthetic Vision System (SVS) (according to the manufacturer the first on a light twin helicopter), a Highway In The Sky (HITS) three-dimensional guidance system, an Enhanced Vision System (EVS), a Helicopter Terrain Awareness and Warning System (HTAWS), dual Global Positioning System (GPS) / Satellite Based Augmentation System (SBAS), dual Flight Management System (FMS) and digital dual duplex four-axis autopilot in a glass cockpit. The avionics enable automatic navigation from take-off to approach.

The Grand New could undertake single pilot instrument flight rules (IFR) operations or employ a dual control cockpit configuration.

Roles comprise EMS, SAR, corporate, VIP, offshore and passenger transport, law enforcement and border patrol but AgustaWestland also developed the specialized mountain rescue / air ambulance Da Vinci version for the Swiss Rega organization.

The AW139, originally AB139, according to AgustaWestland surpasses other medium twins in capability, in speed, 310 kph at cruise, and in range, 1060km.

With a MTOW of 6400kg it could carry one or two crew and up to 15 passengers.

It employs 1250kW FADEC-equipped Pratt & Whitney Canada PT6C-67C engines, a five-bladed articulated main rotor system, four-bladed tail rotor and four-axis digital autopilot.

It could undertake day or night all-weather operations and could auto hover.

Roles include corporate, VIP and offshore transport, EMS, with up to four stretcher patients and up to six attendants, law enforcement and SAR.

The medium/heavy AW101, derived from a military design, stands out as the only helicopter mentioned in this article that uses three engines, the 1880kW FADEC- and inlet-particle-separator-equipped General Electric CT7-8E, through which it also becomes the most powerful helicopter mentioned.

With a MTOW of 15,600kg the AW101 could carry two or three crew and 30 passengers.

It features a five-bladed composite articulated main rotor system, four-bladed articulated tail rotor, part-composite airframe and electrically-folding blade and tail.

Avionics include an Active Control of Structural Response (ACSR) active vibration control system (AVCS), night-vision-goggle-compatible (NVG) glass cockpit with liquid crystal display (LCD) units, dual duplex digital automatic flight control system (AFCS), two avionic mission management computers, health and usage monitoring system (HUMS), cockpit caution and warning system, satellite communications system, Traffic Collision Avoidance System (TCAS) and digital map.

Roles include VIP/head of state transport, SAR and disaster relief.

 

Bell Helicopter

Bell developed the 206L-4 Longranger IV light single through the 206B-3 from the iconic 206.

With a gross weight of 2020kg and payload of 960kg it could carry two crew and five passengers, with a 540kW Rolls-Royce 250-C30P engine, two-bladed rotor system and Nodal Beam suspension system.

It could undertake corporate transport, EMS with two patients and two attendants, utility and law enforcement roles.

The 206L-4 led to the 407 light single with gross weight 2270kg and payload 1,060kg, with the same seating, 490kW Rolls-Royce 250-C47B engine with FADEC and four-bladed main rotor and two-bladed tail rotor with all-composite blades and hub.

From the 407, through the 427 emerged the 429 light twin, which with maximum range 720km and payload 1170kg, Bell says flies farther with more payload than any other helicopter in its class.

With a gross weight of 3180kg, it could carry two crew and six passengers.

It uses 820kW Pratt & Whitney Canada PW207D1 engines with FADEC, composite main rotor blades, hub, rotor, tail boom and tail rotor driveshaft, a double-epoxy-coated ultra-rigid machined-alloy airframe, all-composite external skins, skid or wheel landing gear and a glass cockpit with Bell BasiX-Pro integrated avionics system with dual digital three-axis autopilot, Stability and Control Augmentation System (SCAS) and Integrated Instrument Display System (IIDS), with single pilot IFR certification.

The floats will receive certification for ditching.

Roles include corporate transport, EMS with two litters and three attendants, utility and law enforcement.

Bell could also develop a heavier version and further in the future, envisages a helicopter with an entirely composite fuselage.

The 412 medium twin developed by way of the 212 from the accomplished 204/205.

With a gross weight of 5400kg and payload when IFR-configured of 2270kg it accommodates two crew and 13 passengers; or up to six patients in the disaster management role.

It features 1340kW Pratt & Whitney Canada PT6T-3D Twin Pac engines, composite rotor blades and dual digital AFCS, with certification for single pilot IFR operations.

Cobham Avionics offers an Electronic Flight Information System (EFIS) as an upgrade.

 

Eurocopter

Eurocopter offers the greatest variety of helicopters of current manufacturers.

Its light single-engined types start with the EC120 B Colibri, which with a MTOW of 1720kg and payload 750kg can carry one or two crew and four or three passengers.

It uses a 380kW Turbomeca Arrius 2F engine with bearingless rotor head, composite blades and shrouded Fenestron tail rotor and a digital Vehicle and Engine Multifuntion Display (VEMD).

It could undertake the roles of utility, offshore and corporate transport, training, law enforcement and casualty evacuation (CASEVAC) with a stretcher and attendant. It produces noise 6dB below the ICAO level, according to the manufacturer, the lowest in its class.

The AS350 B2 Ecureuil, with a MTOW of 2250kg and payload of 1030kg could carry a pilot and six passengers.

It uses a 550kW Turbomeca Arriel 1D1 engine, composite Starflex rotor and main and tail rotor blades, advanced control panel, VEMD and dual integrated LCD screen.

Roles encompass passenger and VIP transport, EMS with one stretcher and two attendants, utility, aerial work, training, observation and news gathering, fire-fighting, and law enforcement.

The EC135 light twin with a MTOW of 2910kg and a payload of 1460kg, including one or two crew and seven or six passengers, and a range at MGW of 640km could, according to the manufacturer, carry more payload over longer distances than any other helicopter in its class.

The company also identifies it as the cheapest twin to operate.

It could employ 610kW FADEC-equipped engines of type Turbomeca Arrius 2B2 or Pratt & Whitney Canada PW206B2, with a four-bladed hingeless and bearingless main rotor and Fenestron tail rotor.

It uses sliding side as well as clamshell rear doors.

It features a NVG-compatible Thales Avionics glass cockpit with multifunction LCD displays and Control Panel and Display System (CPDS) with VEMD and a Caution and Advisory Display (CAD).

It could undertake EMS with two stretchers and three attendants, disaster management, SAR, oil and gas industry, passenger, corporate and VIP transport, utility, law enforcement and training.

The EC145 light twin with MTOW 3590kg and payload 1790kg could carry one or two crew and 11 or 10 passengers.

It uses 570kW Turbomeca Arriel 1E2 engines, a hingeless main rotor system, IFR-fitted NVG-compatible cockpit with a VEMD and CAD, variable rotorspeed and torque matching system (VARTOMS) and both side and clamshell rear doors. Roles encompass EMS with two stretchers and three attendants, disaster management, SAR, oil and gas industry, passenger and VIP transport, utility and law enforcement.

The AS365 N3+ Dauphin medium twin with MTOW 4300kg and payload 1850kg could carry one or two crew and up to 11 passengers.

It uses 720kW Turbomeca Arriel 2C engines with a FADEC system, Starflex rotor head, composite main rotor blades and Fenestron tail rotor, digital four-axis autopilot and FMS for EMS with two stretchers and four attendants, SAR, oil and gas industry transport and business, private, parapublic and police roles.

The world’s newest civil helicopter, the EC175 medium twin, developed with Harbin of China, first flew on December 4, 2009.

Able to carry two crew and up to 16 passengers, Eurocopter claims that it possesses the highest payload, performance and range in its class.

It uses 1320kW Pratt & Whitney Canada PT6C-7E engines with FADEC, a five-bladed main rotor, three-bladed tail rotor, Spheriflex minimized bearing rotor head, multifunction LCD displays and four-axis dual duplex autopilot in an open architecture.

Roles include oil and gas industry, corporate and VIP transport, SAR and EMS, with certification envisaged in 2011 and delivery from 2012 and Chinese production from 2013.

Sikorsky Aircraft

The acquisition of the Schweizer Aircraft line allowed Sikorsky to offer helicopters at the lighter end of the turbine range.

The S-434 of gross weight 1320kg and three or four seats, evolved from the previous company’s S-333 with a 313kW Rolls-Royce 250-C20W engine and four-bladed rotor for training, law enforcement, pipeline and powerline patrol, news gathering and light utility missions.

The S-76D variant of the S-76 intermediate twin first flew in February 2009.

With gross weight of 5310kg and payload of 2070kg, the cabin accommodates 12 passengers, with 920kW Pratt & Whitney 210S engines with dual channel FADEC, Quiet Zone transmission, four-bladed articulated rotor system including Quiet Tail Rotor, with composite blades and dual speed rotor, AVCS, Sikorsky-Thales TopDeck avionics system including four-axis autopilot, LCD displays, HUMS and enhanced ground proximity warning system (EGPWS) in an open architecture, with single or dual pilot IFR certification. It also features ice-diverting engine inlets, lightning and High Intensity Radiated Field (HIRF) protection and Emergency Flotation System (EFS), with certification for flight into known icing conditions.

Roles include SAR, EMS, offshore and VIP transport and law enforcement.

Sikorsky says the S-76D offers the lowest direct operating cost in its class.

The S-92, with MTOW 12,020kg and 19-passenger cabin, occupies the heavy end of the twin-engined helicopter range.

Powered by 2040kW General Electric CT7-8A engines with integral particle separator, it features a four-bladed articulated main rotor system, composite blades, AVCS, fuel sponsoons, Rockwell Collins Avionics Management System, FMS, dual digital AFCS, four MFDs, EGPWS, TCAS, HUMS, auto-hover and de-icing systems and bird strike, turbine burst, lightning and HIRF protection.

Roles include offshore, head of state, and executive transport, SAR, with a specialized AFCS, and airline. The company could introduce a hub-mounted vibration suppression (HMVS) system and also flight-tested a fly-by-wire version of the aircraft.

 

Other Manufacturers

Robinson Helicopter achieved its status as the world’s largest producer of civil helicopters through its piston-engined types, particularly the R44 Raven II. However, it now offers the R66 derivative whose greater power comes from the specially-designed 220kW Rolls-Royce RR300 turboshaft engine.

Other current civil helicopters include the US Enstrom Helicopter 480B, Kaman K-MAX with intermeshing rotors and MD Helicopters 520N, 530E/F, 600N and Explorer with NOTAR anti-torque system, indicating that, particularly at the lighter end of the range, relatively small companies continue to offer designs, a good portent for continued innovation.